1. Field of the Invention
The present invention generally relates to a probe card circuit, and more particularly, to a probe card circuit having a debug function.
2. Description of Related Art
In the current highly-developed technical information society, semiconductor devices take up an important position. However, the semiconductor practitioners have to carry out tests repetitiously or add circuits for testing product quality during the fabrication of semiconductor devices or integrated circuits in order to achieve better quality of the products.
FIG. 1 is a circuit diagram of a conventional chip test apparatus. Referring to FIG. 1, the conventional chip test apparatus may test a plurality of tested chips 102, 104, 106, 108 on a wafer. The conventional test apparatus includes a test unit 110 and a probe card 112. The test unit 110 is coupled to the probe card 112 through a plurality of power lines 122, 124, 126, 128 and a signal line 130. The power lines 122, 124, 126, 128 are used for transmitting a test power VDD, and the signal line is used for transmitting a test response signal Vt.
The conventional probe card comprises a plurality of probes. Some of the probes 142, 144, 146, 148 are respectively coupled to the power lines 122, 124, 126, 128, and coupled to the tested chips 102, 104, 106, 108, so as to provide the test power VDD to the tested chips 102, 104, 106, 108. Other probes 152, 154, 156, 158 on the probe card are respectively coupled to a test terminal of the tested chips 102, 104, 106, 108. Thus, when the tested chips 102, 104, 106, 108 generate the test response signal Vt after receiving the test power VDD, the probe card 112 receives the test response signal Vt output by the tested chips 102, 104, 106, 108 through the probes 152, 154, 156, 158.
However, in the conventional test apparatus, if any one of the tested chips 102, 104, 106, 108 is damaged, a short circuit phenomenon may occur. For example, when the tested chip 104 is damaged, the probe 154 may be short-circuited. At this time, the test unit 110 cannot effectively receive the test response signal Vt sent back by the other probes 152, 156, 158. In other words, as long as one of the chips to be tested by the conventional test apparatus is damaged resulting in a short circuit, the test on other chips cannot proceed, and thus those chips will be discarded.